WASHINGTON – The Justice Department sent a legal memorandum to the Pentagon in 2003 asserting that federal laws prohibiting assault, maiming and other crimes did not apply to military interrogators who questioned al-Qaeda captives because the president's ultimate authority as commander in chief overrode such statutes.

The 81-page memo, which was declassified and released publicly yesterday, argues that poking, slapping or shoving detainees would not give rise to criminal liability.

The document also appears to defend the use of mind-altering drugs that do not produce “an extreme effect” calculated to “cause a profound disruption of the senses or personality.”

Although the existence of the memo has long been known, its contents have not been previously disclosed. Nine months after it was issued, Justice Department officials told the Defense Department to stop relying on it. But its reasoning provided the legal foundation for the Defense Department's use of aggressive interrogation practices when captives poured into military jails from Afghanistan and U.S. forces prepared to invade Iraq.

Sent to the Pentagon's general counsel on March 14, 2003, by John Yoo, then a deputy in the Justice Department's Office of Legal Counsel, the memo provides an argument for nearly unfettered presidential power in a time of war. It contends that numerous laws and treaties forbidding torture or cruel treatment should not apply to U.S. interrogations in foreign lands because of the president's inherent wartime powers.

“If a government defendant were to harm an enemy combatant during an interrogation in a manner that might arguably violate a criminal prohibition, he would be doing so in order to prevent further attacks on the United States by the al Qaeda terrorist network,” Yoo wrote. “In that case, we believe that he could argue that the executive branch's constitutional authority to protect the nation from attack justified his actions.”

Interrogators who harmed a prisoner would be protected by a “national and international version of the right to self-defense,” Yoo wrote. He also articulated a definition of illegal conduct in interrogations – that it must “shock the conscience” – that the Bush administration advocated for years.

“Whether conduct is conscience-shocking turns in part on whether it is without any justification,” Yoo wrote, explaining, for example, that it would have to be inspired by malice or sadism before it could be prosecuted.

The declassified memo was sent by the Defense and Justice departments late yesterday to Democrats on Capitol Hill.

The document is similar, though much broader, than a memo primarily written by Yoo in August 2002 that narrowly defined what constitutes illegal torture. That document was also later withdrawn.

In his 2007 book, “The Terror Presidency,” Jack Goldsmith, who took over the Office of Legal Counsel after Yoo departed, writes that the two memos “stood out” for “the unusual lack of care and sobriety in their legal analysis.”

Among many other problems, Goldsmith wrote, both memos “were wildly broader than was necessary to support what was actually being done.”

The documents are among the Justice Department legal memoranda that undergirded some of the highly coercive interrogation techniques employed by the Bush administration, including extreme temperatures, head-slapping and a type of simulated drowning called waterboarding.

In 2005, in the wake of public controversy over such methods, Congress limited Defense Department officials to interrogation methods listed in the Army's field manual, which was rewritten to forbid many of the aggressive methods. The CIA was exempted, however, and President Bush vetoed recent legislation that would have applied the same requirements to that agency.

Yoo, now a law professor at the University of California Berkeley, defended the memo in an e-mail yesterday, saying the Justice Department altered its legal opinions “for appearances' sake.” He said his successors “ignored the department's long tradition in defending the president's authority in wartime.”

“Far from inventing some novel interpretation of the Constitution,” Yoo wrote, “our legal advice to the president, in fact, was near boilerplate.”

Yoo's 2003 memo arrived amid a Pentagon debate about which interrogation techniques should be allowed and which might lead to legal action in domestic and international courts.

After a rebellion by military lawyers, then-Defense Secretary Donald Rumsfeld in December 2002 suspended a list of aggressive techniques he had approved, the most extreme of which were used on a single detainee at the military prison at Guantanamo Bay, Cuba. The prisoner, military investigators later would determine, was subjected to stress positions, nudity, hooding, exposure to dogs and other aggressive techniques.

Largely because of Yoo's memo, however, a Pentagon working group in April 2003 endorsed the continued use of extremely aggressive tactics.

Thomas Romig, who in 2003 was the Army's judge advocate general, said yesterday the memo appears to argue that there are no rules in a time of war, a concept Romig found “downright offensive.”

Martin Lederman, a lawyer formerly with the Office of Legal Counsel who now teaches law at Georgetown University, said the Yoo memo helped create a legal environment that allowed abuses at Abu Ghraib prison in Iraq.

“What else could have been the source of belief in Iraq that the gloves were off and all laws could be disregarded with impunity?” Lederman asked. “It created a world in which everyone on the ground believed the laws did not apply. It was a law-free zone.”

In a 2004 memo for the Navy inspector general's office, then-General Counsel Alberto Mora objected to the idea that cruel, inhuman or degrading treatment could be allowed at Guantanamo and to the concept that the president's authority is virtually unlimited.

Mora wrote that he spoke with Yoo at the Pentagon on Feb. 6, 2003, and that Yoo “glibly” defended his own memo. “Asked whether the President could order the application of torture, Mr. Yoo responded, 'Yes,' ” Mora wrote. Yoo denies saying that.